He revealed his magical ability at an early age. His mother and older sister Minerva worked together to teach him and his younger brother, Robert Jr., that they could not go about showing off their magic. They also worked to conceal the "accidents and embarrassments" that the two boys' magic sometimes caused from their father.[1]

Malcolm eventually fathered at least one child. His offspring would often visit his sister's home in Hogsmeade during her brief marriage between 1981 and 1984.[1]